Jean van gestel and chaeles p



(No Model.)

J. VAN GES TEL & G. F. BECK.

INOANDESGENT ELECTRIC LAMP. No. 322,024. Patented July 14, 1885.

NVENTORS. %1 JAM/4M flfma UNITED STATES PATENT EEicE.

JEAN VAN GFSTEL AND CHARLES F. BECK, OF PARIS, FRANCE; SAID BECK ASSIGNOR TO SAID VAN GESTEL, AND SAID VAN GESTEL ASSIGNOR OF ONE-THIRD TO THOMAS S. HARRISON, OF PHILADELPHIA, PA.

lNCAN DEsCENT ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 322,024, dated July 14, 1885.

Application filed November 24, 1884. (No model.) Patented in France November 6,1884, No. 152,605.

To aZZ whom it may concern.-

Be it known that we, JEAN VAN GESTEL and CHARLES FREDERICK BECK, of Paris, in the Republic of France, have invented certain new anduseful Improvementsin Incandescent Electric Lamps, of which the following is a specification, the accompanying drawings showing a convenient embodiment of the principle upon which the invention depends.

It is a well-known fact in connection with lamps operating by the incandescence of carbon that no light is evolved until the carbon has reached a very high temperature. This is probably due to the great radiating power I 5 possessed by carbon, in consequence of which it parts with its heat so rapidly that the conditions necessary for producing light-rays are I not attained until the temperature is raised far beyond that which suffices to render bodies of less heat-radiating power incandescent.

WVhile carbon possesses the electrical resistance necessary to produce this high temperature under the passage of the current, its tendency to burn and waste away prevents it 2 5 from being used in any atmosphere which will support combustion, and even when protected in the ordinary manner by inclosure in a sealed globe containing inert gas, it is liable to break or spall, and thus loose its continuity. Our invention is based upon the discovery that if a piece of refractory material having a low radiating power of heat be maintained in close contact with a piece of carbon heated by the passage of an electrical current, enough 3 5 heat will be absorbed from the carbon to render the material which is in juxtaposition i11- candescent, and that such incaudescence will be attained at a temperature far below that which would be required if the carbon alone were the source of light. Among the materials adapted to produce this result in connection with carbon, are kaolin, magnesia, and numerous other metallic oxides, refractory to heat, and by preference white in color; but in 5 the following specification we shall refer to kaolin as the type of such materials, without intention, however, of limiting our claim to the use of that particular substance,

Broadly speaking, then, our invention 0011- sists in a combination of which the following are the essential elements: an electrical circuit, maintained through a piece of carbon, and a piece of refractory material having low heat-radiating power arranged in close con tact with the said carbon throughout the whole or aportion of its length.

Minor features of improvement, hereinafter described, consistin suitable holding devices for the carbon and the refractory materiahand means whereby proper contact may be main- 6o tained.

In the accompanying drawings, Figure 1 represents a vertical central section through the lamp; Fig. 2, an exterior view of the cap and device for attaching the circuit-wire there 6 to. Fig. 3 is a view of the end of the carbonholder, with the carbon inserted therein, the direction of view being at right angles to that of Fig. 1. 4 is a similar View of the holder for the refractory material. Fig. 5 is a horizontal section through said holders on the line so a: of Fig. 1, the point of view being below the plane of said section; and Fig.

6 is a vertical section on the line y y, Fig. 1.

In said drawings, A is a glass globe having 7 at its top two necks, a a, and on each side and opposite the center similar necks, a a". The necks a a are respectively provided with screw-caps B B, each of which has a tubular projection, C C, extending down into the globe. WVithin the tube C is a solid copper cylinder or rod, F, sliding freely therein, but maintained in any desired position by means of the set-screws c in the cap B. This cylinder, (which forms the carbon-holder,) has 8 5 at or near its top an opening, d, to admit the end of the wire 1), which leads from the positive pole of the source of electricity, the binding-screw 0 being provided to secure the wire in the opening d. At the bottom of the rod 0 F is an opening, f, extending transversely through the rod and faced on the under side with a small piece of platinum, 9. Above the opening f and opposite to this piece of platinum g is a plate of mica, h, secured by means 5 of a finger, 1;, which projects from the side of the rod F. \Vithin the tube 0 is a hollow copper cylinder, H, provided at its top with similar securing devices and with an attachment for the negative wire n. \Vithin the cylinder H is a coiled spring, I, which presses against a solid cylindrical piece of copper, J,

whose upper end fits snugly within the cyl cent.

\Yithin the lateral neck a is secured a tube of glass, M, or other material, which eX- tends inwardtoward the center of the globe A. lernalfiange, 9', extending around it, to which is attached one endot' the coiled spring It within the tube. To the other end of the coiled spring is attached a cap, S, which is provided with a swivel-door, T, swinging laterally upon a pivot, 11, (see Fig. 6,) and engaging, when closed over the center of the cap, with a lug, it. The outer end of the tube M is closed by a serew-cap, O, engaging with a collar, If, upon the end oi the neck a,

The carbon L, which is preferably a thin strip ofrect-angular cross-section, extends from thecap S horizontally through the opening f of the rod F and abuts against the platinum strip 9 on the end of the cylinder J. To insert the carbon in position the cap 0 is removed and the inner cap, S, is drawn outward until the swivel-door is clear of the tube M, this movement, of course, extending the spring R. The swivel-door T is then swung sidewise, and the carbon strip is inserted and pushed through the center of the spring and through the openingf until it nearly reaches its proper position. \Vhen the swivel-door T is closed so as to engage with the lug w, the spring It draws the cap S within the tube M and holds the carbon firmly against the platinum strip y. As the tension of the spring R is always in this direction, it maintains the contact of the carbon and the strip g, and thus supplies any waste of the carbon which may take place in use. In the opposite neck, is secured a similar tube, M, within which is a coiled spring, Q, attached at each end to plates 1 .l". A setscrew, 0, mounted in the cap O,'which closes the neck c presses against the plate P. The plate I presses against the end of a strip, K, preferably of kaolin or other material equivalent for the purpose of its use, as herein specified. This strip K extends through the openingf of the the cylinder J, and abuts against the mica plate It upon the rod F. The pressure of the spring Q, holds the strip K firmly up against The inner end of this tube M has an in-- the mica. The downward pressure of the spring I within the cylinder H depresses the cylinderJ, and holds the strip K firmly in contact with the upper side of the carbon L, thus making a close contact throughout the whole distance between the ends 01" the can bon-holder F and the kaolin-holder J.

If desired, ventilatingorifices i and .9 may beplaced, respectively, at the top and bottom of the globe A.

The operation of the device is as follows: The connection having been, made with the positive and negative poles at the source of electricity by means of the wires 1) and n, the circuit'is established through the rod F, carbon L, and cylinder J. comes heated by the passage of the current, it communicates its heat to the strip K, which rapidly becomes incandescent, and remains so during the passage of the current through the carbon in juxtaposition with it. As fast as any waste occurs in the carbon or in the strip K, it is supplied by the pressure of the spring It on the one hand or of the spring Q on the other. Thus the circuit is not more than momentarily interrupted, and as it requires an appreciabletimei'orthc strip K to cool down below incandesence, the lamp gives a practically steady and uniform li ht. Furthermore, the temperature at whichincandescence is reached is not so high as to occasion rapid oxidation or wasting of the carbon, and the As the carbon be lamp can thus be used in the ordinary atmosphere.

Having thus described our invention, we claim as new and dcsire to secure by Letters Patent- 1. I11 an electric lamp operating by the contact of a piece of kaolin or equivalent material with a piece of carbon heated by the passage of the current, the combination of a carbon-holder, akaolin-holder, both constructed of metal, and a pressing device arranged to constantly maintain the end of the carbon against the metal of the kaolin-holder.

2. In an electric lamp operating by the contact of a piece of kaolin or equivalent material with a piece of carbon heated by the passage of the current,the combination,with said carbon and said kaolin, of a pressing device, arranged to constantly press the kaolin longitudinally in a plane parallel to that of the carbons surface.

3. In an electric lamp operatingby the contact 01' a piece of kaolin or equivalent material with a piece of carbon heated by the passage of the current, the combination, with said carbon and said kaolin, of a pressing device arranged to constantly press the kaolin laterally in a direction transverse to the plane of the carbon.

4. The holder F, having an opening, f, near its lower end to receive the carbon strip, and provided with set-screws, whereby it may be adjusted vertically.

IOO

5. The combination of the hollow cylinder tached to said spring, and provided with a H, inclosed spring I, and solid cylinder J,. swivel-door, T.

whose upper end fits snugly in the cylinder J EAN VAN GESTEL. H, and whose lower end is provided with a CH. F. BECK. 5 transverse opening to receive the kaolin strip. Witnesses:

6.'The combination of the tube M, the 7M. H. MYERS,

spring R, inclosed therein, and the cap S, at- 1 THOS. M. SMITH. 

